“Students in tribal–dominated Jhabua district in Madhya Pradesh and adjoining villages in Gujarat believe that sacrificing goat can make them pass an exam. Ranapur, 45 km from Jhabua, an idol of Baba Dongar, a tribal god is making all wishes come true. Here, photocopies of exam admit cards are tied around trees and in return for their entreaties coming true, the supplicants promise to offer the god a goat, a hen or a bottle of liquor. Some 500 animals are sacrificed here every day and there are more than a dozen such priests who do the slaughtering.”

The above story is published in TOI and is correct as per mythology provided one understands the mythology.

In mythology riding means controlling and sacrificing means killings and animals are symbolized by human natures and behaviors.

For example, mouse is a vahan of Ganesha and means that to overcome obstacles one need to control one’s greed. Similarly, owl is the vahan of Laxmi and symbolizes that for righteous earning one should be able to control one’s foolishness.

Goats and Rams represent sexuality and sexual desires and lambs represent purity and innocence.
Goat is mentioned in mythology both as a symbol and as a vehicle of Gods. In the Samkhya system Prakriti is depicted as a female goat (Mother Nature). The color of goat is red, black or white representing Sattva, Rajas, and Tamas.

The vehicle of Goddess Kali is a black goat. Agni rides Mesha, a ram. Kubera, the God of wealth, also has a ram as his vehicle. A ram is an uncastrated adult male sheep.

Performing a sacrifice during exams means controlling your tamas or inertia and rajas or aggression, and controlling your sexual desires (uncastrated males).

Brahmacharya in mythology is a period where you are supposed to keep your sexual deviations and other desires under control. So a goat sacrifice does not mean physical killing of goat but killing of goat-like activities within you.